Review ArticlesEndometrial Carcinomas: A Review Emphasizing Overlapping and Distinctive Morphological and Immunohistochemical FeaturesBartosch, Carla MD*; Manuel Lopes, José MD, PhD*,†,‡; Oliva, Esther MD§Author Information *Centro Hospitalar S. João †Faculty of Medicine ‡Institute of Molecular Pathology and Immunology, University of Porto (IPATIMUP), Porto, Portugal §Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA The authors have no funding or conflicts of interest to disclose. Reprints: Esther Oliva, MD, Pathology Department (Warren 2), Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114 (e-mail: firstname.lastname@example.org). All figures can be viewed online in color at http://http://www.anatomicpathology.com. Advances In Anatomic Pathology: November 2011 - Volume 18 - Issue 6 - p 415-437 doi: 10.1097/PAP.0b013e318234ab18 Buy Metrics Abstract This review focuses on the most common diagnostic pitfalls and helpful morphologic and immunohistochemical markers in the differential diagnosis between the different subtypes of endometrial carcinomas, including: (1) endometrioid versus serous glandular carcinoma, (2) papillary endometrioid (not otherwise specified, villoglandular and nonvillous variants) versus serous carcinoma, (3) endometrioid carcinoma with spindle cells, hyalinization, and heterologous components versus malignant mixed müllerian tumor, (4) high-grade endometrioid versus serous carcinoma, (5) high-grade endometrioid carcinoma versus dedifferentiated or undifferentiated carcinoma, (6) endometrioid carcinoma with clear cells versus clear cell carcinoma, (7) clear cell versus serous carcinoma, (8) undifferentiated versus neuroendocrine carcinoma, (9) carcinoma of mixed cell types versus carcinoma with ambiguous features or variant morphology, (10) Lynch syndrome-related endometrial carcinomas, (11) high-grade or undifferentiated carcinoma versus nonepithelial uterine tumors. As carcinomas in the endometrium are not always primary, this review also discusses the differential diagnosis between endometrial carcinomas and other gynecological malignancies such as endocervical (glandular) and ovarian/peritoneal serous carcinoma, as well as with extra-gynecologic metastases (mainly breast and colon). © 2011 Lippincott Williams & Wilkins, Inc.